Pirn



Sept. 24, 1968 w. L. SCHMIDT PIRN Filed Jan. 9, 1967 INVENTOR. WILLIAM L. SCHMIDT WVW ATTORNEYS.

United States Patent 3,402,902 PIRN William L. Schmidt, Gastonia, N.C., assignor to Cocker Machine & Foundry Company, Gastonia, N.C., a corporation of North Carolina Filed Jan. 9, 1967, Ser. No. 608,147 2 Claims. (Cl. 242-11831) ABSTRACT OF THE DISCLOSURE A pirn having an end plug and means for retaining the end plug within the barrel portion of the pirn. This means comprises a substantially flat strip having a serrated edge having generally inwardly extending teeth which are irnbedded in the side wall of the plug at a location intermediate the ends thereof.

Cross-reference to related application Reference is made to my copending U.S. patent application No. 522,212, filed Jan. 21, 1966, now Patent No. 3,368,767.

Background of the invention The textile industry utilizes many types of pirns, bobbins and tubes. The uses to which these pirns, etc. have been put, has led to the development of a number of similar design criteria, which in turn has resulted in similar structural elements and characteristics, among which are: (1) a barrel of steel, aluminum alloy or other comparably strong material; (2) a soft outer sleeve or sheath of plastic or other suitable material disposed about the barrel; and -(3) a plug at one or both ends of the barrel.

Retaining this plug within the barrel in a fixed position so that, for example, rotary motion may be transmitted through the plug to the barrel to cause the barrel to rotate, has been fraught with problems. It has been found to be desirable to use tough, resilient materials, e.g., nylon, for the plug, because if impact loading and other reasons not pertinent to this disclosure. However, plugs of this material have a tendency to work loose with the passage of time.

To combat this problem, numerous bushings of various configurations have been developed to retain such nylon plugs in the barrel. In the prior art, these bushings have often been intricately formed to close tolerances, and therefore, have been relatively expensive to produce.

Summary of the invention The present invention provides a simple, inexpensive and effective means for retaining the plug of a textile pirn in the barrel of the pirn, which means comprises a strip having a serrated edge with inwardly extending teeth which are irnbedded in the side wall of the plug at a location intermediate the ends of said plug, said strip being disposed wholly between said barrel .and said plug, which means provides increased holding power by virtue of its improved spring-like construction and unique gripping edge.

Accordingly, it is an object of this invention to provide a simple, effective and novel retaining means for retaining the plug of a textile pirn within the barrel of the pirn, which means is disposed wholly between said barrel and said plug and intermediate the ends of said plug.

Another object of this invention is to provide a retaining means for retaining the plug of a fiangeless textile pirn within the barrel of the pirn, which means is disposed wholly between said barrel and said plug, and inter- 3,402,902 Patented Sept. 24, 1968 "ice Brief description of the drawings FIG. 1 represents a sectional view of an embodiment of an assembled pirn constructed in accordance with the features of this invention, the pirn being shown in position on a driving whorl and spindle which are shown in phantom elevation;

FIG. 2 is an enlarged view, partially in section, of the subassembly comprising the retaining means and the plug; this subassembly being shown prior to insertion into the sheathed barrel of the pirn, which is shown in phantom;

FIG. 3 is an enlarged sectional view of a portion of the assembled pirn shown in FIG. 1, showing the retaining means and plug in assembled position with the sheathed barrel of the pirn.

Description of the preferred embodiment Although specific forms of the invention have been selected for illustration in the drawing, and the following description is drawn in specific terms for the purpose of describing those forms of the invention, this description is not intended to limit the scope of the invention, which is defined in the claims.

Referring to the drawing, FIG. 1 shows the pirn generally designated 1, as having an elongated cylindrical barrel 10 and having a plug 11 at its upper end, and a plastic sheath 12 covering a substantial part of the barrel 10 and curled over the upper portion of the plug 11. Located at the base of the pirn is a driven plug 13. The pirn 1, as shown, is disposed on the driving portion of a whorl 14. Extending through the whorl 14 is a spindle 17 of any suitable type as is well known in the art. Located at a point spaced along the axis of the pirn 1 from its base is a spindle bearing 20 'which is spaced below the tip 21 of the spindle 17.

The structure thus described is similar to that described in detail in my copending application 'Ser. No. 522,212, -filed Jan. 21, 1966, entitled Textile Pirn, and accordingly, it will be appreciated that the pirn 1 is adapted to be driven by a rotating whorl 14 which mates with the driven plug 13 of the pirn.

Referring to the figures, driven plug 13 is shown in subassembled position (FIG. 2) with the retaining means 30 (described in detail hereinafter), prior to insertion of the subassembly into the barrel 10. The driven plug 13 is preferably made of material such as molded nylon having desirable characteristics of strength and resiliency. The driven plug 13 has a generally cylindrical periphery 22 which fits closely inside the sheath 12 (FIG. 1) and has an inwardly shouldered portion 23, which, when assembled as in FIGS. 1 and 3, abuts against the lower end 5 of the barrel 10. An upwardly projecting flange 24 of reduced diameter, fits snugly within the end of the barrel 10 (FIGS. 1 and 3), and has an inwardly shouldered portion 25. A still further reduced diameter section 26 forms the inner end portion of the driven plug 13.

The interior configuration of the driven plug 13 may vary considerably depending on the spindle base with which it is to be used, and other uses to which it may be put.

The retaining means 30 is shown in FIG. 2 in its relaxed or uncompressed condition. It is disposed on the inwardly shouldered portion 25 of the driven plug 13, which shouldered portion will maintain the retaining means 30 in axial position when the subassembly is driven into the barrel 10 to form the fiangeless pirn assembly 1, as in FIGS. 1 and 3. The retaining means 30 is preferably made of sheet metal, and comprises a single substantailly fiat strip having a serrated edge 32 with preferably inwardly extending teeth as at 33 (FIGS. 2 and 3).

By a comparison of FIGS. 2 and 3, it can be seen that the thickness of the metal forming the retaining means 30 is approximately the same as the width of the shoulder 25, so that without the inwardly extending teeth, the retaining means 30 would be in an approximately line to line fit with the inside diameter of the barrel 10. After the serrations have been formed in the substantially flat metal strip forming the retaining means 30, and the strip has been permanently deformed so that the teeth protrude inwardly, the space occupied by the retaining means 30, in its position on the shoulder 25, will be sufificiently in excess of the inside diameter of the barrel 10 to cause compression of the retaining means 30 when it is inserted into the barrel 10 and to imbed, thereby, the teeth into the cylindrical surface of the reduced diameter section 26 of the driven plug 13, at a location intermediate the ends 40 and 41 of said driven plug 13, as shown in FIG. 3. The imbedding of these teeth provides a positive retention means for retaining the resilient driven plug 13 in the barrel 10.

It has been found that the permanent deformation of the strip forming the retaining means 30 by the forming of the serrations in such a manner that the teeth project inwardly, provides excellent outwardly directed radial force characteristics to retain the retaining means 30 in the barrel 10 after the driven plug 13 has been inserted into the barrel by virtue of the attempt of the retaining means 30 to return to its permanently deformed shape as shown in FIG. 2.

The resilience of the driven plug material provides radially directed outward forces, which aid the retaining means 30 in locking into the surface of the reduced diameter section 26 of the driven plug 13. These forces will be increased by having an increased wall thickness at 29 (FIG. 3) which will provide a stiffer section 26. Thus, by having the retaining means 30 disposed wholly between the driven plug 13 and the barrel 10, the maximum Wall thickness at 29 can be achieved, because this thickness can now be carried radially inwardly as far as the surface of the mating portion of the whorl 14. This characteristic also increases the effectiveness of the forced fit between the retaining means 30 and the barrel 10, as will readily be understood from the drawings, since it aids the retaining means 30 in its attempt to regain its original uncompressed condition as shown in FIG. 2.

It will be understood that the invention described provides a very simple and effective retaining means for retaining a plug of a pirn within the barrel of the pirn, which means has an improved forced fit between the retaining means and the inside surface of the barrel, and an improved locking action between the plug and the retaining means by virtue of its unique shape and disposition Within the assembled pirn. Another advantage of this simple design is that it eliminates the need for closely held tolerances and is therefore easier and less expensive to make.

Furthermore, assembly is also made easier and less expensive. The plug 13 may be assembled with the retaining means 30 to form a simple subassembly (FIG. 2), which subassembly can then be forced into the barrel 10 of the pirn 1 (FIG. 3). Forcing the retaining means 30 into the barrel 10, automatically forces the teeth into the reduced diameter section 26. Thus there is no need for an added operation, such as first affirmatively attaching the retaining means 30 to the plug 13 before assembly with the barrel 10.

It can readily be appreciated that what I have said regarding the disposition and function of the retaining means 30, and its coaction with the driven plug 13 and the barrel 10, applies equally to the plug 11.

Thus, referring to FIG. 1, the plug 11 also has a generally cylindrical periphery 22a which fits closely inside the sheath 12 and has an inwardly shouldered portion 23a, which, when assembled, abuts against the end 5a of the barrel 10. A flange of reduced diameter 24a, fits snugly within the end of the barrel 10 and has an inwardly shouldered portion 250. A still further reduced diameter section 26a forms the inner end portion of the plug 11.

The retaining means 30a is identical to the retaining means 30 and is disposed in the assembled pirn on the shoulder 25a of the plug 11 in exactly the same manner and to function in exactly the same way as the retaining means 30 is disposed on and functions with the driven plug 13.

It will be understood that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a pirn having a cylindrical barrel and a generally cylindrical plug formed of yieldable material and provided with an end portion disposed in the end of the barrel, the improvement which comprises: a narrow horizontal annular shoulder formed on the end portion of the plug and providing an annular zone of smaller outer diameter than the inner diameter of the barrel, and an annular metallic strip having a thickness equal to the width of said shoulder and having one edge thereof seated on said shoulder, said strip having radially inwardly extending teeth on its other edge engaging the plug at said annular zone, said strip being inclined outwardly and upwardly prior to insertion of the end portion of the plug into the barrel to provide a wedge-like formation which is collapsed inwardly upon insertion of the end portion of the plug into the barrel to cause said teeth to be embedded into the plug at said annular zone and said strip to be forced-fitted into the barrel.

2. The improvement according to claim 1, including aplug portion of increased thickness located outwardly of the portion of the plug in which said annular zone is formed.

References Cited UNITED STATES PATENTS 205,246 6/1878 Crowley 242l 18.31 1,893,320 1/1933 Baldwin 242-118.31 2,953,317 9/1960 Atwood et al. 242-118.31 3,132,817 5/1964 Atwood et al. 242-4621 GEORGE F. MAUTZ, Primary Examiner, 

